A filament lamp is generally used as a lamp for a dashboard or a license plate of a mechanical tool, a vehicle or the like including various kinds of electronic products. The filament lamp is inserted on the top of a socket and illuminates a room as the filament emits light when electrical power is applied through the socket, which facilitates indoor activities at night or in a dark place.
However, since the general filament lamp described above frequently experiences open circuit of the filament by a physical or electrical impact, the lifespan of the filament lamp is short. This creates a troublesome problem of having to replace the lamp frequently and incurring economic loss due to such frequent replacement, thereby burdening the user.
Therefore, various attempts have been made devising a lamp using an LED in order to overcome the disadvantages associated with the conventional lamp described above.
Generally, a light emitting diode (LED) is a lighting equipment which emits light by forward current. Since it is very robust to an impact, has a semi-permanent lifespan and is comparatively cheap. The light emitting diode is widely used in various fields and is commonly used in any place in which illumination is needed such as a dashboard of a vehicle, an audio system, an air conditioner and the like. In addition, since the light emitting diode needs to be supplied with power to operate and compositely configured together with other circuit elements, it is mounted on a printed circuit board and a mounting structure is required.
LED is a structure in which two through-holes spaced apart from each other are formed on a printed circuit board to communicate the top and bottom surfaces. Two legs of the light emitting diode are inserted into the through-holes and welded to a copper film on the printed circuit board by means of soldering. If the legs of the light emitting diode are inserted into the through-holes formed on the printed circuit board from a side opposite to the surface of the printed circuit board on which the copper film is formed, then the copper film and the end points of the legs of the light emitting diode are welded by soldering at the side on which the copper film of the printed circuit board is formed. The light emitting diode is fixed to the printed circuit board and mounting of the light emitting diode is completed.
However, if the light emitting diode is mounted on the printed circuit board in such conventional structure, the legs of the light emitting diode should be welded and fixed to the copper film through soldering. This leads to a problem in that productivity is lowered because the work time is extended due to degradation in workability. Furthermore, once the light emitting diode is mounted on the printed circuit board, it is difficult to separate and replace a damaged light emitting diode lamp.
It is known that Korean Utility Model Registration No. 20-261626 entitled “Structure of mounting a substrate of a light emitting diode for illumination” has been proposed to solve the above problems to certain extent.
A pair of connectors are inserted into mounting grooves of a socket to be spaced apart from each other. A light emitting diode is coupled to the connectors by inserting the legs (lead frames) of the light emitting diode into the connectors to contact the inner surfaces of the connectors. However, since a pair of connectors are simply inserted and loaded in a space unit formed inside the socket, the loaded state of the connectors can be released due to external vibrations or the like to make the connectors loose or dislodge the light emitting diode. If the lead frames of the light emitting diode coupled to the inner surfaces of the connectors do not maintain a linear state and are bent, contact failure may occur between the light emitting diode and the connectors.
In addition, since a wire which supplies power to the lead frames of the light emitting diode directly contacts the connectors connected to a ground protrusion by welding, an external impact applied to the light emitting diode is directly transferred to the connectors. The welded state of the ground protrusion can be released or contact failure can occur from the external impact directly transferred to the connectors, thereby lowering the quality.